U.S. patent number 5,830,940 [Application Number 08/683,246] was granted by the patent office on 1998-11-03 for shaped article of liquid crystalline polymer.
This patent grant is currently assigned to Toray Industries, Inc.. Invention is credited to Toshihide Inoue, Norio Kitajima, Kiyokazu Nakamura.
United States Patent |
5,830,940 |
Nakamura , et al. |
November 3, 1998 |
**Please see images for:
( Certificate of Correction ) ** |
Shaped article of liquid crystalline polymer
Abstract
The present invention relates to a shaped article of a liquid
crystalline polymer containing (A) 100 parts by weight of a liquid
crystalline polyester and/or liquid crystal polyesteramide capable
of forming an anisotropic melt and (B) 0.01 to 2 parts of an
olefinic polymer and having a retention rate of a weld strength of
15% to 100%, which has excellent heat stability, mechanical
properties, dimensional stability and mold releasability and is
suitable for various application uses such as electrical and
electronical related devices, accurate machine related devices,
office related devices, automobile related parts.
Inventors: |
Nakamura; Kiyokazu (Aichi,
JP), Kitajima; Norio (Aichi, JP), Inoue;
Toshihide (Aichi, JP) |
Assignee: |
Toray Industries, Inc.
(JP)
|
Family
ID: |
27480371 |
Appl.
No.: |
08/683,246 |
Filed: |
July 18, 1996 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
628396 |
Apr 5, 1996 |
5643988 |
|
|
|
365026 |
Dec 28, 1994 |
|
|
|
|
Foreign Application Priority Data
|
|
|
|
|
Dec 28, 1993 [JP] |
|
|
5-338096 |
Dec 27, 1994 [JP] |
|
|
6-326469 |
|
Current U.S.
Class: |
524/404; 524/415;
525/152; 525/133; 525/132; 524/514; 524/449; 524/451; 524/452;
524/513; 524/406; 524/413; 524/456; 524/445; 524/425 |
Current CPC
Class: |
C08L
77/12 (20130101); B29C 45/0001 (20130101); C08L
67/00 (20130101); C08L 67/00 (20130101); C08L
2666/06 (20130101); C08L 77/12 (20130101); C08L
2666/04 (20130101); C08L 77/12 (20130101); C08L
23/00 (20130101); B29K 2105/0079 (20130101); C08L
23/00 (20130101) |
Current International
Class: |
C08L
67/00 (20060101); B29C 45/00 (20060101); C08L
77/12 (20060101); C08L 77/00 (20060101); C08L
067/03 (); C08L 067/04 (); C08L 077/12 () |
Field of
Search: |
;525/132,133,152
;524/449,451,513,514,404,413,406,415,425,445,452,456 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
0 111 179 A1 |
|
Jun 1984 |
|
EP |
|
0 369 734 A3 |
|
May 1990 |
|
EP |
|
0 382 486 A3 |
|
Aug 1990 |
|
EP |
|
0 380 112 Ae |
|
Aug 1990 |
|
EP |
|
0 462 844 A3 |
|
Dec 1991 |
|
EP |
|
A-49-72393 |
|
Jul 1974 |
|
JP |
|
A-5477691 |
|
Jun 1979 |
|
JP |
|
A-57-24407 |
|
Feb 1982 |
|
JP |
|
A-57-172921 |
|
Oct 1982 |
|
JP |
|
62-241995 |
|
Oct 1987 |
|
JP |
|
A-63-146959 |
|
Jun 1988 |
|
JP |
|
A-64-33123 |
|
Feb 1989 |
|
JP |
|
A-01 121 357 |
|
May 1989 |
|
JP |
|
A-1 197 555 |
|
Aug 1989 |
|
JP |
|
A-01 292 057 |
|
Nov 1989 |
|
JP |
|
A-2-208035 |
|
Aug 1990 |
|
JP |
|
A-4-120162 |
|
Apr 1992 |
|
JP |
|
A-04 202 461 |
|
Jul 1992 |
|
JP |
|
A-6 073 272 |
|
Mar 1994 |
|
JP |
|
WO-A-92 18568 |
|
Oct 1992 |
|
WO |
|
Other References
Rubber Digest vol. 27, No. 8, pp. 7-14, 1975..
|
Primary Examiner: Short; Patricia A.
Attorney, Agent or Firm: Miller; Austin R.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part application of Ser. No.
08/628,396 filed Apr. 5, 1996, now U.S. Pat. No. 5,643,988 which is
a continuation application of Ser. No. 08/365,026 filed Dec. 28,
1994, now abandoned.
Claims
We claim:
1. A shaped article of a liquid crystalline polymer having a weld,
which is provided by plural melted resin flows encountering in a
mold, obtained by melt molding a composition comprising (A) 100
parts by weight of at least one liquid crystalline polymer capable
of forming an anisotropic melt selected from the group consisting
of liquid crystalline polyesters and liquid crystalline polyester
amides and (B) 0.01 to 2 parts by weight of at least one olefinic
polymer, having a weight-average molecular weight of 10,000 to
600,000, selected from the group consisting of (a) polyethylene,
(b) polypropylene, (c) copolymers of ethylene and .alpha.-olefin
having 3 or more carbon atoms, (d) copolymers of propylene and
.alpha.-olefin having 4 or more carbon atoms, (e) copolymers of
ethylene, .alpha.-olefin having 3 or more carbon atoms and a
non-conjugated diene and (f) copolymers of propylene,
.alpha.-olefin having 4 or more carbon atoms and a non-conjugated
diene, and (C) 400 parts by weight or less of a filler selected
from the group consisting of carbon fiber, aromatic polyamide
fiber, potassium titanate fiber, gypsum fiber, brass fiber,
stainless steel fiber, steel fiber, ceramic fiber, boron whisker
fiber, asbestos fiber, mica, talc, silica, calcium carbonate, glass
beads, glass flakes, glass microballoons, clay, molybdenum
disulfide, wollastonite, titanium oxide, calcium polyphosphate,
graphite, granular and plate fillers, based upon 100 parts by
weight of the liquid crystalline polymer (A), said composition
having a retention rate of a weld strength of 15% to 100% obtained
by the following formula (1), based upon flexural strengths
determined from a weld shaped article (X) having a weld, which is
provided by plural melted resin flows encountering in the mold, at
substantially the center portion thereof and a non-weld shaped
article (Y) having no weld therein, both obtained by injection
molding the composition under the following conditions:
Injection molding condition:
Cylinder temperature: Melting point (.degree.C.) of liquid
crystalline polymer+10.degree. C.
Mold temperature: 90.degree. C.
Size of shaped article: 6.0 mm (width).times.127 mm
(length).times.1 mm (thickness).
2. A shaped article as claimed in claim 1, having the weld portion
with a retention rate of a weld strength is 20% to 100%.
3. A shaped article as claimed in claim 1, wherein the liquid
crystalline polymer (A) is at least one polymer selected from the
group consisting of fully aromatic liquid crystalline polyesters,
fully aromatic liquid crystalline polyesteramides, liquid
crystalline polyesters having an ethylenedioxy unit, and liquid
crystalline polyesteramides having an ethylenedioxy unit.
4. A shaped article as claimed in claim 3, wherein the liquid
crystalline polymer (A) is at least one polymer selected from the
group consisting of liquid crystalline polyesters having an
ethylenedioxy unit and liquid crystalline polyesteramides having an
ethylenedioxy unit.
5. A shaped article as claimed in claim 4, wherein the liquid
crystalline polyester (A) is at least one liquid crystalline
polyesters composed of the following structural units (I), (III)
and (IV), liquid crystalline polyesters composed of the following
structural units (I), (II) and (IV), and liquid crystalline
polyesters having the following structural units (I), (II), (III)
and (IV): ##STR10## wherein R.sub.1 represents at least one group
selected from the group consisting of: ##STR11## and R.sub.2
represents at least one group selected from the group consisting
of: ##STR12## wherein X represents a hydrogen atom or chlorine
atom, and the total number of moles of structural unit (II) and
structural (III) are substantially equal to the total of the number
of moles of structural unit (IV).
6. A shaped article as claimed in claim 1, wherein said fillers are
surface treated with a silane or titanate coupling agent.
7. A shaped article as claimed in claim 1, wherein said composition
contains 70 to 200 parts by weight of said filler, based upon 100
parts by weight of the liquid crystalline polymer (A).
8. A shaped article as claimed in claim 1, wherein the
weight-average molecular weight of the olefinic polymer is 30,000
to 600,000.
9. A shaped article as claimed in claim 1 further comprising 0.5 to
60 parts by weight of an organic bromine compound selected from the
group consisting of hexabromobenzene, pentabromotoluene,
hexabromobiphenyl, decabromobiphenyl, hexabromocyclodecane,
decabromobiphenylether, octabromodiphenylether,
hexabromodiphenylether, bis(pentabromophenoxy)ethane,
ethylene-bis(tetrabromophthalimide), tetrabromobisphenol A,
brominated polycarbonate oligomers, copolymers of brominated
polycarbonate oligomers with bisphenol A that are manufactured
using brominated bisphenol A as a raw material, brominated diepoxy
compounds obtained by reaction of brominated bisphenol A and
epichlorohydrin, monoepoxy compounds obtained by reaction of
brominated phenols and epichlorohydrin, condensation products of
poly(brominated benzylacrylate), brominated polyphenylene ether,
brominated bisphenol A, cyanuryl chloride, brominated phenol,
halogenated polymers and halogenated oligomers, based upon 100
parts by weight of the liquid crystalline polymer (A).
10. A shaped article of a liquid crystalline polymer having a weld,
which is provided by plural melted resin flows encountering in a
mold, obtained by melt molding a composition comprising (A) 100
parts by weight of at least one liquid crystalline polymer capable
of forming an anisotropic melt selected from the group consisting
of liquid crystalline polyesters and liquid crystalline polyester
amides and (B) 0.01 to 2 parts by weight of at least one olefinic
polymer, having a weight-average molecular weight of 10,000 to
600,000, selected from the group consisting of (a) polyethylene,
(b) polypropylene, (c) copolymers of ethylene and .alpha.-olefin
having 3 or more carbon atoms, (d) copolymers of propylene and
.alpha.-olefin having 4 or more carbon atoms, (e) copolymers of
ethylene, .alpha.-olefin having 3 or more carbon atoms and a
non-conjugated diene and (f) copolymers of propylene,
.alpha.-olefin having 4 or more carbon atoms and a non-conjugated
diene, and (C) 0.5 to 60 parts by weight of an organic bromine
compound selected from the group consisting of hexabromobenzene,
pentabromotoluene, hexabromobiphenyl, decabromobiphenyl,
hexabromocyclodecane, decabromobiphenylether,
octabromodiphenylether, hexabromodiphenylether,
bis(pentabromophenoxy)ethane, ethylene-bis(tetrabromophthalimide),
tetrabromobisphenol A, brominated polycarbonate oligomers,
copolymers of brominated polycarbonate oligomers with bisphenol A
that are manufactured using brominated bisphenol A as a raw
material, brominated diepoxy compounds obtained by reaction of
brominated bisphenol A and epichlorohydrin, monoepoxy compounds
obtained by reaction of brominated phenols and epichlorohydrin,
condensation products of poly(brominated benzylacrylate),
brominated polyphenylene ether, brominated bisphenol A, cyanuryl
chloride, brominated phenol, halogenated polymers and halogenated
oligomers, based upon 100 parts by weight of the liquid crystalline
polymer (A), said composition having a retention rate of a weld
strength of 15% to 100% obtained by the following formula (1),
based upon flexural strengths determined from a weld shaped article
(X) having a weld, which is provided by plural melted resin flows
encountering in a mold, at substantially the center portion thereof
and a non-weld shaped article (Y) having no weld therein, both
obtained by injection molding the composition under the following
conditions:
Injection molding condition:
Cylinder temperature: Melting point (.degree.C.) of liquid
crystalline polymer+10.degree. C.
Mold temperature: 90.degree. C.
Size of shaped article: 6.0 mm (width).times.127 mm
(length).times.1 mm (thickness).
11. A shaped article as claimed in claim 10, wherein said organic
bromine compound is included in an amount in the composition at a
bromine content of 20% by weight or more.
12. A shaped article as claimed in claim 10, wherein said
composition contains 1 to 30 parts by weight of said organic
bromine compound, based upon 100 parts by weight of the liquid
crystalline polymer (A).
13. A shaped article as claimed in claim 10, wherein said organic
bromine compound is dispersed in the composition at an average
diameter of 25 .mu.m or less.
14. A shaped article as claimed in claim 10, having the weld
portion with a retention rate of a weld strength is 20% to
100%.
15. A shaped article as claimed in claim 10, wherein the liquid
crystalline polymer (A) is at least one polymer selected from the
group consisting of fully aromatic liquid crystalline polyesters,
fully aromatic liquid crystalline polyesteramides, liquid
crystalline polyesters having an ethylenedioxy unit, and liquid
crystalline polyesteramides having an ethylenedioxy unit.
16. A shaped article as claimed in claim 15, wherein the liquid
crystalline polymer (A) is at least one polymer selected from the
group consisting of liquid crystalline polyesters having an
ethylenedioxy unit and liquid crystalline polyesteramides having an
ethylenedioxy unit.
17. A shaped article as claimed in claim 16, wherein the liquid
crystalline polyester (A) is at least one liquid crystalline
polyesters composed of the following structural units (I), (III)
and (IV), liquid crystalline polyesters composed of the following
structural units (I), (II) and (IV), and liquid crystalline
polyesters having the following structural units (I), (II), (III)
and (IV): ##STR13## wherein R.sub.1 represents at least one group
selected from the group consisting of: ##STR14## and R.sub.2
represents at least one group selected from the group consisting
of: ##STR15## wherein X represents a hydrogen atom or chlorine
atom, and the total number of moles of structural unit (II) and
structural unit (III) are substantially equal to the total of the
number of moles of structural unit (IV).
18. A shaped article as claimed in claim 10, wherein the
weight-average molecular weight of the olefinic polymer is 30,000
to 600,000.
19. A shaped article as claimed in claim 10, wherein said
brominated diepoxy compound is represented by the general formula
(i): ##STR16## wherein n is 15 or more.
20. A shaped article as claimed in claim 10, wherein the brominated
polycarbonate oligomer is represented by formula (iv): ##STR17##
wherein R.sup.3 and R.sup.4 represent substituted or unsubstituted
aryl groups, and n is 4 or more.
21. A shaped article as claimed in claim 10, wherein the
composition further contains 0.01 to 10 parts by weight of carbon
black, based upon 100 parts by weight of the liquid crystalline
polymer (A).
Description
BACKGROUND OF THE INVENTION
(A) Field of the Invention
The present invention relates to a shaped article of a liquid
crystalline polymer having excellent mold releasability from a die
when molding, having excellent thermal and chemical stability
without generating decomposition gases etc., having a weld with
excellently balanced thermal stability exhibiting a low decrease in
strength of a weld, mechanical properties and moldability and
having excellent dimensional stability.
(B) Description of the Prior Art
The need for plastic materials having high performance have been
growing in recent years. Numerous polymers having various new types
of performance have been developed and marketed. However, optical
anisotropic liquid crystalline polymers characterized by the
parallel sequences of molecular chains, have particularly noted due
to their superior flowability, thermal resistance, mechanical
properties, and mechanical stability. Examples of such polymers
capable of forming an anisotropic melt include, for example, a
liquid crystal polyester obtained by copolymerizing
polyethyleneterephthalate with p-hydroxybenzoic acid (Japanese
Unexamined Patent Publication No. 49-72393), a liquid crystalline
polyester obtained by copolymerizing p-hydroxybenzoic acid and
6-hydroxy-2-naphthoic acid (Japanese Unexamined Patent Publication
No. 54-77691), a liquid crystal polyester obtained by
copolymerizing 4,4'-dihydroxybiphenyl, terephthalic acid and
isophthalic acid with p-hydroxybenzoic acid (Japanese Examined
Patent Publication No. 57-24407), a liquid crystalline polyester
amide formed from 6-hydroxy-2-naphthoic acid, p-aminophenol and
terephthalic acid (Japanese Unexamined Patent Publication No.
57-172921), and a liquid crystalline polyesteramide formed from
p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl, terephthalic acid,
p-aminobenzoic acid and polyethylene terephthalate (Japanese
Unexamined Patent Publication No. 64-33123).
However, it is also well known in the art that these liquid
crystalline polymers have problems including large mechanical
anisotropy and dimensional anisotropy. For solving these problems,
various attempts have been made. For example, a method wherein a
glass fiber is added to a liquid crystalline polymer (Rubber
Digest, Vol. 27, No. 8, pp. 7-14, 1975), a method wherein powder in
the form of a plate or flake such as mica, talc or graphite is
compounded into a liquid crystalline polymer (Japanese Unexamined
Patent Publication No. 63-146959). Thus, the anisotropy is relaxed
(or decreased) and simultaneously the mechanical properties,
thermal resistance, moldability and dimensional stability are
further improved. As a result, the liquid crystalline polymer
compositions are used, as an engineering plastic, in a wide variety
of application fields, such as automobile parts, electrical and
electronic parts, precise mechanical parts, office machine
parts.
Since liquid crystalline polymers are generally excellent in the
flowability thereof, the molding and processing are easy and the
liquid crystalline polymers can be used as thin-walled molded
products or molded articles having complicated shapes. However,
various problems have been pointed out in the molding of such
thin-walled molded products and molded articles having complicated
shapes such that the dimensional stability thereof becomes poor due
to poor mold releasability, the operation to remove the molded
articles from the mold, and the productivity is decreased.
Generally, as a method for improving the mold releasability,
methods for adding various releasing agents such as fatty acid
esters, metal salts of fatty acids, fatty acid amides, low
molecular weight polyethylene polymers are added to the liquid
crystalline polymers are known in the art. In addition, Japanese
Unexamined Patent Publication No. 2-208035 discloses a method for
formulating fatty acid esters to liquid crystalline polyesters and
Japanese Unexamined Patent Publication No. 4-120162 discloses a
method for adding fatty acid esters composed of polyols (e.g.,
glycerol and pentaerythritol) and fatty acids having 12 or more
carbon atoms.
However, when these methods are applied to liquid crystalline
polymers, there cause other problems, due to the high processing
temperature of the liquid crystalline polymers, that the releasing
agents decomposes to generate volatile gases, and therefore, not
only the outside appearance of the molded articles is adversely
affected, but also the effects of the releasing agents are
impaired, whereby the release of the molded article from the die
becomes poor and the shape of the molded article is changed (or
deformed). Especially, in the case of molded articles having a weld
(i.e., which is provided by plural melted resin flows encountering
in the mold), the strength at the weld is largely decreased and the
strength of the molded articles become poor and the molded articles
cannot be practically used due to the shortage in the strength of
the molded articles, especially in the weld thereof.
SUMMARY OF THE INVENTION
Accordingly, the objects of the present invention are to obviate
the above-mentioned problems and to provide a shaped article of a
liquid crystalline resin having excellent mold releasibility from a
mold when molded, having good thermal and chemical stability
without causing the deformation of the molded articles and without
generating the decomposed gases, having small decrease in the
strength of the weld, having the weld with the balanced excellent
properties of thermal resistance, mechanical properties and
moldability, and excellent dimensional stability.
Other objects of the present invention are to provide shaped
articles, e.g., three-dimensional molded articles, sheets, vessels,
pipes, of liquid crystalline polymer useful in the various
application fields, including electrical and electronic parts
represented by various gears, various cases sensors, LEP lamps,
connectors, sockets, resistors, relay case switches, coil bobbins,
condensers, variable condensers, optical pickups, oscillators,
various types of terminal boards, transformers, plugs, printed
circuit boards, tuners, speakers, microphones, headphones, small
motors, magnetic head bases, power modules, semiconductors, FDD
carriages, FDD chassis motor brush holders, parabolic antennas and
computer parts; home appliance and electrical office product parts
represented by VTR parts, television parts, irons, hair dryers,
rice cooker parts, microwave oven parts, audio parts, audio
equipment parts such as those for audio laser disks and compact
disks, lighting parts, refrigerator parts, air conditioner parts,
typewriter parts and word processor parts; mechanical parts
represented by office computer parts, telephone parts, facsimile
parts, copier parts, cleaning tools, oilless bearings, stern
bearings, water bearings, motor parts, lighters and typewriters;
optical equipment and precision machinery parts represented by
microscopies, binoculars, cameras and clocks; and, automotive and
vehicular parts such as alternator terminals, alternator
connectors, IC regulators, potentiometer bases, various valves such
as exhaust gas valves, various fuel, exhaust and air intake pipes,
air intake nozzle snorkels, intake manifolds, fuel pumps, engine
coolant joints, carburetor main bodies, carburetor spacers, exhaust
gas sensors, coolant sensors, oil temperature sensors, brake pad
wear sensors, throttle position sensors, crankshaft position
sensors, air flow meters, brake pad wear sensors, air conditioner
thermostat bases, heater air flow control valves, radiator motor
brush holders, water pump impellers, turbine vanes, wiper motor
parts, distributors, starter switches, starter relays, transmission
wire harnesses, window washer nozzles, air conditioner panel switch
plates, fuel system solenoid valve coils, fuse connectors, horn
terminals, electrical equipment insulating plates, step motor
rotors, lamp sockets, lamp reflectors, lamp housings, blake
pistons, solenoid bobbins, engine oil filters and ignition device
cases.
The following provides a description of the constitution for
achieving the objects of the present invention.
In accordance with the present invention, there is provided a
shaped article of a liquid crystalline polymer having a weld, which
is provided by plural melted resin flows encountering in the mold,
obtained by melt molding a composition comprising (A) 100 parts by
weight of at least one liquid crystalline polymer selected from the
group consisting of liquid crystalline polyesters and liquid
crystalline polyester amides capable of forming an anisotropic
melt; and (B) 0.01 to 2 parts by weight of at least one olefinic
polymer selected from the group consisting of (a) polyethylene, (b)
polypropylene, (c) copolymers of ethylene and .alpha.-olefin having
3 or more carbon atoms, (d) copolymers of propylene and
.alpha.-olefin having 4 or more carbon atoms, (e) copolymers of
ethylene, .alpha.-olefin having 3 or more carbon atoms and a
non-conjugated diene and (f) copolymers of propylene,
.alpha.-olefin having 4 or more carbon atoms and a non-conjugated
diene and having a weight-average molecular weight of 10,000 to
600,000, said composition having a retention rate of a weld
strength 15% to 100% obtained by the following formula (1), based
upon flexural strengths determined from a weld shaped article (X)
having a weld, which is provided by plural melted resin flows
encountering in the mold, at substantially the center portion
thereof and a non-weld shaped article (Y) having no weld, both
obtained by injection molding the composition under the following
conditions:
Injection molding condition:
Cylinder temperature: Melting point (.degree.C.) of liquid
crystalline polymer+10.degree. C.
Mold temperature: 90.degree. C.
Size of shaped article: 6.0 mm (width).times.127 mm
(length).times.1 mm (thickness).
In accordance with the present invention, there is also provided
the above-mentioned shaped article having a weld with a retention
rate of the weld of 20% to 100%.
In accordance with the present invention, there is further provided
the above-mentioned shaped article, wherein the liquid crystalline
polymer (A) is at least one polymer selected from the group
consisting of fully aromatic liquid crystalline polyesters, fully
aromatic liquid crystalline polyesteramides, liquid crystalline
polyesters having an ethylenedioxy unit, and liquid crystalline
polyesteramides having an ethylenedioxy unit.
In accordance with the present invention, there is still further
provided the above-mentioned shaped article, wherein the liquid
crystalline polyester (A) is at least one liquid crystalline
polyesters composed of the following structural units (I), (III)
and (IV), liquid crystalline polyesters composed of the following
structural units (I), (II) and (IV), and liquid crystalline
polyesters having the following structural units (I), (II), (III)
and (IV): ##STR1## wherein R.sub.1 represents at least one group
selected from the group consisting of: ##STR2## and R.sub.1
represents at least one group selected from the group consisting
of: ##STR3## wherein X represents a hydrogen atom or chlorine atom,
and the total number of moles of structural unit (II) and
structural (III) are substantially equal to the total of the number
of moles of structural unit (IV).
In accordance with the present invention, there is still further
provided the above-mentioned shaped article, wherein the
composition further contains 400 parts by weight or less of a
filler, based upon 100 parts by weight of the liquid crystalline
polymer (A).
In accordance with the present invention, there is still further
provided the above-mentioned shaped article, wherein the
composition further contains 0.5 to 60 parts by weight of an
organic bromine compound based upon 100 parts by weight of the
liquid crystalline polymer (A).
In accordance with the present invention, there is still further
provided the above-mentioned shaped article, wherein the organic
bromine compound is poly(brominated styrene) having a weight
average molecular weight of 1.times.10.sup.3 to 120.times.10.sup.4
and having at least one following structural unit obtained from
brominated styrene monomer as the major structural component.
##STR4## In accordance with the present invention, there is sill
further provided the above-mentioned shaped article, wherein the
composition further contains 0.01 to 10 parts by weight of carbon
black, based upon 100 parts by weight of the liquid crystalline
polymer (A).
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be better understood from the
description set forth below with reference to the accompanying
drawings of FIGS. 1 and 2, which schematically illustrate
perspective views of a weld molded article (X) and a box-type
molded article obtained in Example 1, respectively.
PREFERRED EMBODIMENTS OF THE INVENTION
In the present invention, as the component (A), at least one liquid
crystalline polymer selected from liquid crystalline polyesters and
liquid crystalline polyesteramides both capable of forming an
anisotropic melt is used.
The liquid crystalline polyesters and the liquid crystalline
polyesteramides capable of forming an anisotropic melt referred to
in the present invention are liquid crystalline polyesters which
form an anisotropic melt comprising structural units selected from
structural units such as an aromatic oxycarbonyl unit, an aromatic
dioxy unit, an aromatic dicarbonyl unit and an ethylenedioxy unit,
and liquid crystalline polyesteramides capable of forming an
anisotropic melt comprising structural units such as the
above-mentioned structural units, an aromatic iminocarbonyl unit,
an aromatic diimino unit and an aromatic iminooxy unit.
The liquid crystalline polyester and/or polyesteramide capable of
forming an anisotropic melt used in the present invention may be an
fully aromatic thermotropic polyester, preferably one having a
naphthalene ring, an fully aromatic thermotropic polyesteramide,
preferably one having a naphthalene ring, a liquid crystalline
polyester having ethylenedioxy units, or a liquid crystalline
polyesteramide having ethylenedioxy amide capable of forming an
anisotropic molten phase.
Preferable examples of liquid crystalline polyesters include liquid
crystalline polyesters comprising the structural units of (I),
(III) and (IV), (I), (II) and (IV) or (I), (II), (III) and (IV).
Among these, the use of the liquid crystalline polyester having the
structural unit of (I), (II) and (IV) or having the structural unit
of (I), (II), (III) and (IV) is preferable.
Structural unit (I) is a structural unit of a polyester formed from
p-hydroxybenzoic acid. Structural unit (II) represents a structural
unit formed from an aromatic dihydroxy compound selected from
4,4'-dihydroxybiphenyl, 3,3'5,5'-tetramethyl-4,4'-dihydroxyphenyl,
hydroquinone, t-butylhydroquinone, phenylhydroquinone,
2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene,
2,2-bis(4-hydroxyphenyl)propane and 4,4'-dihydroxyphenylether.
Structural unit (III) represents a structural unit formed from
ethyleneglycol. Structural unit (IV) represents a structural unit
formed from an aromatic dicarboxylic acid selected from
terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic
acid, 2,6-naphthalenedicarboxylic acid,
1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid,
1,2-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylic acid and
4,4'-diphenylether dicarboxylic acid.
Among these, the especially preferable one is that having R.sub.1
of: ##STR5## and having R.sub.2 of ##STR6##
The liquid crystalline polymers preferably usable in the present
invention are liquid crystalline polyesters comprising the
above-mentioned structural units (I), (II) and (IV) or (I), (II),
(III) and (IV), and the copolymerization amounts of the
above-mentioned structural units (I), (II), (III) and (IV) are not
limited, However, the following copolymerization amounts are
preferable in consideration of the flowability property
thereof.
Namely, in the case of those containing the above-mentioned
structural unit (III), the molar fraction of the total of the
structural units (I) and (II) to the total of the above-mentioned
structural units (I), (II) and (III) is preferably 60 to 95 mol %,
particularly preferably 75 to 93 mol % in consideration of the
thermal resistance, flame resistance and mechanical properties
thereof. In addition, the molar fraction of the structural unit
(III) to the total of the structural units (I), (II) and (III) is
preferably 40 to 5 mol %, particularly preferably 25 to 7 mol
%.
In addition, the molar fraction ratio (I)/(II) of the structural
unit (I) to the structural unit (II) is preferably 75/25 to 95/5,
and particularly preferably 78/22 to 93/7 in consideration of the
balance between the thermal resistance and the flowability.
Furthermore, it is preferable that, the total number of moles of
the structural unit (II) and the structural unit (III) is
substantially equal to the number of moles of the structural unit
(IV). The term "substantially" used herein means that, if desired,
the number of either of the carboxy end group or the hydroxyl end
group in the end group of the polyester can be made larger, but in
such a case, the total number of moles of the structural units (II)
and (III) is not completely equal to the number of moles of the
structural unit (IV).
On the other hand, in the case of those not containing the
above-mentioned structural unit (III), the molar fraction of the
structural unit (I) to the total of the structural units (I) and
(II) is preferably 40 to 90 mol %, and particularly preferably 60
to 88 mol %. It is preferable that the number of moles of the
structural unit (II) is substantially equal to the number of moles
of the structural unit (IV). In this case, the meanings of the term
"substantial" is the same as mentioned in the above case including
the unit (III). This is the same as in the case of the liquid
crystalline polyesters having the structural units of (I), (III)
and (IV).
Furthermore, when the above-mentioned liquid crystalline polyesters
particularly preferably usable in the present invention is
polycondensates, aromatic dicarboxylic acids such as
3,3'-diphenyldicarboxylic acid and 2,2'-diphenyldicarboxylic acid,
aliphatic dicarboxylic acids such as adipic acid, azelaic acid,
sebacic acid and dodecanedionic acid, alicyclic dicarboxylic acids
such as hexahydroterephthalic acid, aromatic diols such as
chlorohydroquinone, methylhydroquinone,
4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfide and
4,4'-dihydroxybenzophenone, aliphatic and alicyclic diols such as
1,4-butanediol, 1,6-hexanediol, neopentylglycol,
1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, aromatic
hydroxycarboxylic acids such as m-hydroxybenzoic acid and
2,6-hydroxynaphthoic acid, and p-aminophenol and p-aminobenzoic
acid can be additionally used, other than the above-mentioned
components forming the structural units (I) to (IV) within a range
of low proportions to an extent that does not impair the object of
the present invention.
In addition to the above structural units (I) to (IV), as the
liquid crystalline polyester amides, the polyester amides capable
of forming an anisotropic melt phase and containing a p-imino
phenoxy unit formed from p-aminophenol.
There are no particular limitations to the process for producing
the above-mentioned liquid crystalline polyesters preferably usable
in the present invention and the liquid crystalline polyesters and
polyesteramides can be produced according to any known polyester or
polyesteramide condensation polymerization methods.
For example, in the case of those not containing the
above-mentioned structure unit (III) can be preferably produced by
the following methods (1) and (2), and in the case of those
containing the structural unit (III) can be preferably produced by
the following method (3).
(1) A production process using a condensation polymerization with
the removal of acetic acid from a diacrylated product of
p-acetoxybenzoic acid, an aromatic dihydroxy compound such as
4,4'-diacetoxybiphenyl or para-4,4'-diacetoxybenzene, and an
aromatic dicarboxylic acid such as terephthalic acid.
(2) A production process using a condensation polymerization
reaction with the removal of acetic acid from the reaction of
p-hydroxybenzoic acid and an aromatic dihydroxy compound such as
4,4'-dihydroxybiphenyl or hydroxyquinone, and acetic anhydride with
an aromatic dicarboxylic acid such as terephthalic acid, followed
by acylation of phenolic hydroxyl groups.
(3) A production process according to the above-mentioned (1) or
(2) carried out in the presence of a polymer or oligomer such as
polyethylene terephthalate, or a bis(.beta.-hydroxyether)ester of
an aromatic dicarboxylic acid such as
bis(.beta.-hydroxyethyl)terephthalate.
In addition, these condensation polymerization reactions can be
carried out without using a catalyst, but a catalyst may be
optionally used. Typical examples of such catalysts usable in the
condensation polymerization reaction include metal compounds such
as stannous acetate, tetrabutyltitanate, potassium acetate, sodium
acetate, antimony trioxide and magnesium metal.
The logarithmic viscosity (or inherent viscosity) of the liquid
crystal polymer (A) according to the present invention can be
measured in pentafluorophenol. It is preferable that the value
measured at 60.degree. C. at a concentration of 0.1 g/dl is at
least 0.5 dl/g, and particularly in the case of those containing
the above-mentioned structural unit (III), the value of 1.0 to 3.0
dl/g is preferable. On the other hand, in the case of those not
containing the above-mentioned structural unit (III), the
logarithmic viscosity (or inherent viscosity) value of 2.0 to 10.0
dl/g is preferable.
In addition, the melt viscosity of the liquid crystal polymer (A)
usable in the present invention is preferably 10 to 20,000 poise,
and more preferably 20 to 10,000 poise.
Furthermore, the above-mentioned melt viscosity refers to the value
measured at a temperature 10.degree. C. higher than the melting
point (Tm)(.degree.C.) of the liquid crystal resin (A) (i.e.
Tm+10.degree. C.) using a Koka type flow tester under the
conditions of a shear rate of 1,000 (1/sec) and a nozzle size of
0.5 mm in diameter by 10 mm in length.
The melting point (Tm)(.degree.C.) referred herein represents the
endothermic peak temperature which is observed when the measurement
is carried out at a temperature-elevating rate of 20.degree. C./min
by using a differential scanning calorimeter, i.e., Tm.sub.2,
described hereinafter.
For the differential scanning calorimetric measurement described
above, a polymer obtained by polymerization is heated from room
temperature to a temperature exceeding the melting point at a
temperature-elevating rate of 20.degree. C./min, and the observed
endothermic peak temperature (hereinafter referred to as "Tm.sub.1
") is measured. After the measurement of Tm.sub.1, the polymer is
maintained at a temperature of Tm.sub.1 +20.degree. C. for 5
minutes, followed by cooling once down to room temperature at a
temperature-dropping rate of 20.degree. C./min, and the temperature
is then elevated at a rate of 20.degree. C./min. The endothermic
peak temperature (hereinafter referred to as "Tm.sub.2 ") measured
at this second run is measured.
The olefinic polymer usable in the present invention is at least
one olefinic polymer selected from the group consisting of (a)
polyethylene, (b) polypropylene, (c) copolymers of ethylene and
.alpha.-olefin having 3 or more carbon atoms, preferably 3 to 20
carbon atoms, (d) copolymers of propylene and .alpha.-olefin having
4 or more carbon atoms, preferably 4 to 20 carbon atoms, (e)
copolymers of ethylene, .alpha.-olefin having 3 or more carbon
atoms, preferably 3 ti 20 carbon atoms, and a non-conjugated diene
and (f) copolymers of propylene, .alpha.-olefin having 4 or more
carbon atoms, preferably 4 to 20 carbon atoms, and a non-conjugated
diene.
Examples of the preferable .alpha.-olefins having 3 or more carbon
atoms are propylene, butene-1, pentene-1, 3-methylpentene-1,
octacene-1. These may be used alone or in any mixture thereof. The
use of propylene and butene-1 is further preferable.
Examples of the preferable .alpha.-olefins having 4 or more carbon
atoms are those having 3 or more carbon atoms exemplified above,
other than propylene. These may be used alone or in any mixture
thereof.
Examples of the preferable non-conjugated dienes are
5-ethylidene-2-norbornene, dicydopentadiene and 1,4-hexadiene.
Again, these non-conjugated dienes may be used alone or in any
mixture thereof.
The ratio of ethylene/.alpha.-olefin having 3 or more carbon atoms
in the copolymer thereof according to the present invention is
preferably 40/60-99/1 (mole ratio), more preferably 70/30-95/5
(mole ratio). The ratio of propylene .alpha.-olefin having 4 or
more carbon atoms in the copolymer thereof is preferably 40/0-99/1
(mole ratio), more preferably, 70/30-95/5 (mole ratio).
The ethylene content of the ethylene/C.sub.3 or more
.alpha.-olefin/non-conjugated diene copolymer is preferably 5-96.9
mole %, more preferably 30-84.5 mole %. The amount of
.alpha.-olefin having 3 or more carbon atoms is preferably 3-80
mole %, more preferably 15-60 mole %, and the amount of
non-conjugated diene is preferably 0.1-15 mole %, more preferably
0.5-10 mole %. Furthermore, the propylene content of the
propylene/.alpha.-olefin having C.sub.4 or more carbon
atoms/non-conjugated diene is 5-96.9 mole % more preferably 30-84.5
mole % and the content of .alpha.-olefin having 4 or more carbon
atoms is preferably 3-80 mole %, more preferably 15-60 mole %, and
the content of the non-conjugated diene is preferably 0.1 to 15
mole %, more preferably 0.5 to 10 mole %.
Examples of the above-mentioned copolymers are ethylene/propylene
copolymer, ethylene/butene-1 copolymer, ethylene/pentene-1
copolymer, ethylene/propylene/butene-1 copolymer,
propylene/pentene-1 copolymer, propylene/butene-1 copolymer,
propylene/pentene-1 copolymer, propylene/butene-1 copolymer,
ethylene/propylene/5-ethylidene-2-nonbornene copolymer,
ethylene/propylene/1,4-hexadiene copolymer,
propylene/butene-1/1,4-hexadiene copolymer,
ethylene/propylene/dicyclopentadiene copolymer, etc. Among these,
the use of ethylene/propylene copolymer and
ethylene/butene-1copolymer are especially preferable due to the
excellent thermal stability thereof. These olefinic copolymers may
be used alone or in any mixture thereof. In addition, it is
preferable from the viewpoint of the flowability of the resultant
composition that a comonomer having an epoxy and/or carboxylic acid
group is not copolymerized therein.
The above-mentioned olefinic polymers should have a weight-average
molecular weight of 10,000 to 600,000, preferably 30,000 to
500,000, more preferably 100,000 to 450,000. The use of a low
molecular weight polyethylene having a weight-average molecular
weight of less than 10,000, well known as a releasing agent is not
preferable because the releasing effect thereof is poor and
decrease in the weld strength and the gas burning are unpreferably
caused when the weight average molecular weight is more than
600,000, the decreases in the flowability and the physical
properties unpreferably occur.
The amount of the olefinic polymer should be 0.01 to 2 parts by
weight, preferably 0.05 to 1.90 parts by weight, more preferably
0.1 to 1.80 parts by weight, based upon 100 parts by weight of the
liquid crystalline polymer. When amount is less than 0.01 parts by
weight, the intended improvement effect of the mold releasibility
cannot be obtained, whereas the use of the amount of more than 2
parts by weight, the weld strength is unpreferably decreased.
According to the present invention, fillers can be optionally
incorporated into the liquid crystalline polymer composition.
Examples of such fillers are glass fiber, carbon fiber, aromatic
polyamide fiber, potassium titanate fiber, gypsum fiber, brass
fiber, stainless steel fiber, steel fiber, ceramic fiber, boron
whisker fiber, asbestos fiber, mica, talc, silica, calcium
carbonate, glass beads, glass flakes glass microballoon, clay,
molybdenum disulfide, wollastonite, titanium oxide, calcium
polyphosphate, graphite, granular, or plate-like fillers. Among the
above fillers, the use of the glass fiber is preferable.
The types of the glass fibers are not specifically limited as far
as glass fibers are generally used for reinforcing resins. For
example, the glass fiber can be selected from chopped strands,
milled fibers, etc. of long-fiber or short-fiber types.
The amount of the above-mentioned fillers, when used, is preferably
400 parts by weight or less, more preferably 50 to 250 parts by
weight, particularly preferably 70 to 200 parts by weight, based
upon 100 parts by weight of the liquid crystalline polymer.
Further, these fillers usable in the present invention may be
treated by a silane type, titanate type, or other coupling agent or
other known surface treatment agent, on the surface thereof.
Further, the glass fiber may be coated or combined with a
thermoplastic resin such as ethylene/vinyl acetate copolymer or a
thermosetting resin such as epoxy resin.
According to the present invention, organic bromine compounds can
be further included in the composition.
The organic bromine compound optionally usable in the present
invention includes known organic bromine compounds normally used as
a flame retardant, and is preferably included in the present
polymer composition at a bromine content of 20% by weight or more.
The preferable examples thereof include low molecular weight
organic bromine compounds such as hexabromobenzene,
pentabromotoluene, hexabromobiphenyl, decabromobiphenyl,
hexabromocyclodecane, decabromobiphenylether,
octabromodiphenylether, hexabromodiphenylether,
bis(pentabromophenoxy)ethane, ethylene-bis(tetrabromophthalimide)
and tetrabromobisphenol A, brominated polycarbonates (for example,
polycarbonate oligomers or their copolymers with bisphenol A that
are manufactured using brominated bisphenol A as the raw material),
brominated epoxy compounds (for example, diepoxy compounds obtained
by reaction of brominated bisphenol A and epichlorohydrin, and
monoepoxy compounds obtained by reaction of brominated phenols and
epichlorohydrin), condensation products of poly(brominated
benzylacrylate), brominated polyphenylene ether, brominated
bisphenol A, cyanuryl chloride and brominated phenol, halogenated
polymers and oligomers such as brominated polystyrene, crosslinked
brominated polystyrene and crosslinked brominated
poly-.alpha.-methylstyrene, or mixtures of these. Particularly
preferable examples include ethylene-bis(tetrabromophthalimide),
brominated epoxy oligomers or polymers, brominated polystyrene,
crosslinked brominated polystyrene, brominated polyphenylene ether
and brominated polycarbonate, the brominated polystyrene being used
most preferably.
The following provides a more detailed description of the
above-mentioned preferable organic bromine compound. A preferable
example of a brominated epoxy polymer is represented by the
following general formula (i). ##STR7##
In the above-mentioned general formula (i), n is preferably 15 or
more, and more preferably 50 to 80.
Examples of the brominated polystyrenes usable in the present
invention include brominated polystyrene manufactured by
brominating a polystyrene obtained by radical or anionic
polymerization, or the poly(brominated styrene) having brominated
styrene units represented with formula (ii) and/or (iii)
manufactured by radical or anionic polymerization, but preferably
radical polymerization, of brominated styrene monomer. However,
poly(brominated styrene) having a weight average molecular weight
of 1.times.10.sup.3 to 120.times.10.sup.4, and having the
structural unit represented with the formula (ii) and/or (iii)
indicated below, obtained from a brominated styrene monomer as its
major structural unit, is preferable. ##STR8##
The brominated styrene monomer referred to here is preferably that
wherein 2 to 3 bromine atoms are introduced by a substitution
reaction into the aromatic ring, which may contain monobrominated
styrene and so forth, in addition to dibrominated styrene and/or
tribrominated styrene.
The preferable above-mentioned poly(brominated styrene) contains at
least 60% by weights and more preferably at least 70% by weight, of
dibrominated styrene and/or tribrominated styrene units. Thus, the
poly(brominated styrene) may also include 40% by weight or less,
and preferably 30% by weight or less, of monobrominated styrene
copolymerized therewith, in addition to dibrominated styrene and/or
tribrominated styrene. The weight average molecular weight of the
poly(brominated styrene) is more preferably 1.times.10.sup.4 to
15.times.10.sup.4. Furthermore, the weight average molecular weight
used herein refers to the value as measured using a gel permeation
chromatography, which is a relative value, based on the molecular
weight of polystyrene.
The crosslinked brominated polystyrene is preferably a polystyrene
resulting from the bromination of porous polystyrene crosslinked
with divinylbenzene.
Preferable examples of the brominated polycarbonate are those
having the general formula (iv) indicated below. ##STR9## wherein
R.sup.3 and R.sup.4 represent substituted or unsubstituted aryl
groups, most preferably p-t-butylphenyl group.
In the above-mentioned general formula (iv), the degree of
polymerization n is preferably 4 or more, particularly preferably 8
or more, and more particularly preferably 8 to 25.
The amount of these organic brominated compounds is preferably 0.5
to 60 parts by weight, and more preferably 1 to 30 parts by weight,
based upon 100 parts by weight of liquid crystalline polymer.
In addition, the organic brominated compound in the flame-retardant
liquid crystalline polymer composition of the present invention is
preferably dispersed at an average diameter of 25 .mu.m or less,
and more preferably at a average diameter of 2.0 .mu.m or less, in
the composition.
Furthermore, in the present invention, carbon black can be further
formulated in the composition. Although there are no specific
limitations to the types of the carbon black usable in the present
invention, those having a pH of 3-10, more preferably having a pH
of 5-9 can be preferably used from the viewpoint of the mechanical
properties of the resultant composition.
Furthermore, the liquid crystal polymer composition of the present
invention can be given the desired properties by adding
conventional additives and the other thermoplastic resins within
the range to an extent which does not impair the object of the
present invention. Examples of such additives include, for example,
antioxidants and heat stabilizers (e.g. hindered phenol,
hydroquinone, phosphates and their substituted forms), UV
absorbents (e.g. resorcinol, salicylate, benzotriazole and
benzophenone), lubricants, coloring agents containing dyes (e.g.
nigrosine) and pigments (e.g. cadmium sulfate, phthalocyanine),
plasticizers, auxiliary frame retardant and antistatic agents and
other thermoplastic resins (e.g., fluorine resin).
The shaped article of liquid crystalline polymer according to the
present invention can be produced any method, without limitation.
For example, the shaped article according to the present invention
can be produced by, for example, producing the liquid crystalline
polymer composition by melt mixing, followed by melt molding the
resultant composition.
The melt-mixing (or kneading) methods of the liquid crystalline
composition according to the present invention are not specifically
limited. For example, the composition can be produced by
melt-mixing and kneading at 200.degree. to 400.degree. C. using,
for example, a Banbury mixer, rubber rolls, kneader or single or
twin-screw extruder for melting and kneading. In particular,
according to the recommendable method, a twin-screw extruder is
used to separately and continuously feed (A) the liquid crystalline
polymer (B) the olefinic polymer and the other optional additives
such as glass fiber.
As mentioned above, according to the present invention, the liquid
crystalline polymer composition should have a retention rate of a
weld strength of 15% to 100%, preferably 20% to 100%, particularly,
preferably 25% to 100%, determined by the following method. When
the retention rate of a weld strength is less than 15%, the
strength of the weld of the liquid crystalline polymer shaped
article is low and is not practically acceptable. Although the
upper limit is preferably 100%, the retention rate of up to 60% is
particularly acceptable.
The retention rate of the weld strength can be determined according
to the present invention as follows.
(1) The test piece (i.e., molded article) is prepared as
follows.
A. Test piece
The test piece is prepared by an injection molding under the
following conditions
Cylinder temperature: (Melting point (.degree.C.) of liquid
crystalline polymer (A)+10).degree.C.
Mold temperature: 90.degree. C.
Size of shaped article: 6.0 mm (width).times.127 mm
(length).times.1 mm (thickness)
More specifically, weld molded articles (X) having a weld, which is
provided by plural melted resin flows encountering in the mold,
around the center portion of 6.0 mmW.times.127 mmL.times.1 mmT are
prepared by injection molding, using a mold provided with gates
having a width of 3 mm at the positions of 3 mm from the both edge
portions in the lengthwise direction, under the conditions of a
cylinder temperature of an injection molding machine of (the
melting point of liquid crystalline polymer (A)+10)(.degree.C.) and
a mold temperature of 90.degree. C. Furthermore, non-weld molded
articles (Y) having no weld is prepared from one gate by injection
molding under the same conditions (i.e., a cylinder temperature of
an injection molding machine of (the melting point of the liquid
crystalline polymer (A)+10)(.degree.C.) and a mold temperature of
90.degree. C.
Note: As an error for the condition setting in an injection molding
machine, the following ranges are usually allowable.
Cylinder temperature: (Melting point of liquid crystalline polymer
(A)+10)(.degree.C.).+-.8.degree. C.
Mold temperature: 90.degree. C..+-.10.degree. C.
Size of molded article: 6.0 mm.+-.0.30 mm (width).times.127 mm.+-.3
mm (length).times.1 mm.+-.0.2 mm (thickness)
When the melting point of the liquid crystalline polymer used in
the evaluation is difficult to determine, the cylinder temperature
can be substituted with a temperature of (liquid crystal initiation
temperature+40)(.degree.C.) and the allowable error range is
(liquid crystal initiation temperature+40)(.degree.C.).+-.8.degree.
C.
FIG. 1 shows a perspective view of the weld molded article (X),
obtained by injection molding (l) having a size of 127 mm (length
L.sub.1).times.6.0 mm (width W.sub.1).times.1 mm (thickness
t.sub.1) wherein the two gate positions 2 are provided at the
position of 3 mm from the both edge portions in the lengthwise
direction.
(2) Determination method of retention rate of weld strength
The test pieces obtained above are adjusted at a temperature of
23.degree. C..+-.2.degree. C. (i.e., room temperature), a relative
humidity of 50%.+-.5% for 15 hours.
Then, the flexural strengths of, the weld molded article (X) and
non-weld molded article (Y) are determined under the conditions of
a spun distance of 20 mm and a strain rate of 0.7 mm/min. The
retention rate of weld strength is calculated by substituting the
determined value of the flexural strength to the equation (1).
Thus, the determination of the retention rate of weld strength is
determined from the following equation (1), based upon flexural
strengths determined from a weld molded article (X) having a weld
at substantially the center portion thereof and a non-weld molded
article (Y) having no weld:
The molded article of the liquid crystalline polymer according to
the present invention can be produced by melt molding the
above-mentioned liquid crystalline composition. As the melt molding
method, there are no specific limitation and various molding
methods including injection molding, extrusion molding and blow
molding. Among these methods, injection molding can be preferably
used. As a preferable injection molding method, it is recommendable
to feed the above-mentioned liquid crystalline polymer composition
to an in-line type injection molding machine set at a temperature
within the range of Tm-30.degree. C. to Tm+50.degree. C. (Note:
Tm=melting point of the liquid crystalline polymer composition) (or
when the melting point is difficult to determine, a temperature
within the range of the liquid crystalline initiation
temperature+10.degree. C. to the liquid crystalline initiation
temperature+90.degree. C.), followed by injection molding to a mold
having a shape corresponding to the desired article and set at a
mold temperature of about 70.degree. C. to about 150.degree. C.
Thus, the molded article of liquid crystalline composition having a
weld can be molded.
The molded article according to the present invention can be
molded, for example, as mentioned above, but it is necessary that
the molded article has at least one weld.
The "weld" used herein means a portion which is provided by plural
melted resin flows encountering in the mold. The both resins may be
the same or the different.
EXAMPLES
The present invention will now be further illustrated by, but is by
no means limited to, the following Examples.
Reference Example 1
A 994 part by weight amount of p-hydroxybenzoic acid, 126 parts by
weight of 4,4'-dihydroxybiphenyl, 112 parts by weight of
terephthalic acid, 216 parts by weight of polyethylene
terephthalate having an inherent viscosity of approximately 0.6
dl/g and 960 parts by weight of acetic anhydride were charged into
a reaction vessel equipped with a stirrer and a distillation tube
to obtain the desired liquid crystalline polymer (A) by the
completion of condensation polymerization. The melting point of the
resultant polymer (A) was 314.degree. C. and a melt viscosity at
324.degree. C. and a shear rate of 1,000/sec was 400 poise.
Reference Example 2
A 994 part by weight amount of p-hydroxybenzoic acid, 222 parts by
weight of 4,4'-dihydroxybiphenyl, 147 parts by weight of
2,6-diacetoxynaphthalene, 1078 parts by weight of acetic anhydride
and 299 parts by weight of terephthalic acid were charged into a
reaction vessel equipped with a stirrer and a distillation tube to
obtain the desired polymer (B) by the completion of condensation
polymerization.
The melting point (Tm) of this polymer was 336.degree. C. and a
melt viscosity at a temperature of 346.degree. C. and a shear rate
of 1,000/sec was 520 poise.
Reference Example 3
A 1296 parts by weight amount of p-acetoxybenzoic acid and 346
parts by weight of polyethylene terephthalate having an inherent
viscosity of approximately 0.6 dl/g were charged into a reaction
vessel equipped with a stirrer and a distillation tube according to
Japanese Unexamined Patent Publication No. 49-72393, followed by
condensation polymerization to obtain the desired polymer (C)
having a melting point (Tm) of 283.degree. C. and a melt viscosity
at a temperature of 293.degree. C. and a shear rate of 1,000/sec
was 1,200 poise.
Reference Example 4
A 921 parts by weight amount of p-acetoxybenzoic acid and 435 parts
by weight of 6-acetoxy-2-naphthoic acid were charged into a
reaction vessel equipped with a stirrer and distillation tube
according to Japanese Unexamined Patent Publication No. 54-77691,
followed by condensation polymerization to obtain the desired
polymer (D) having a melting point (Tm) of 283.degree. C. and a
melt viscosity at a temperature of 293.degree. C. and a shear rate
of 1,000/sec of 2,000 poise.
Examples 1-4 and Comparative Example 1-5
The liquid crystalline polymers obtained in Reference Examples 1-4
were dry blended with olefinic polymers listed in Table 1 in
amounts shown in Table 1. Thereafter, the blend was melt kneaded to
obtain the pellets, using a twin-screw extruder having a diameter
of 30 mm in which the cylinder temperature were set to the melting
point of each polymer. The resultant pellets were then fed into the
Sumitomo Nestal Promat 40/25 Injection Molding Machine (Sumitomo
Heavy Machine Industry K.K.) and injection molded into weld molded
products (X) having a weld at substantially the center portion
thereof and non-weld molded products (Y) having no weld having a
size of 6 mmW.times.127 mmL.times.1 mmT under the conditions of a
cylinder temperature of Tm+10.degree. C. and a mold temperature of
90.degree. C.
The molded products were adjusted at a temperature of
23.degree..+-.2.degree. C. and a relative humidity of 50.+-.5% for
15 hours or more and, then, the flexural strengths of the weld
molded product (X) having a weld at substantially the center
portion thereof and a non-weld molded product (Y) having no weld
were determined at a span distance of 25 mm and a strain rate of 1
mm and the retention rate of the weld strength was obtained by
substituting the values of the flexural strengths to the equation
(1):
Furthermore, the above pellets were fed to Toshiba 1S55 EPN
injection molding machine (Toshiba Kikai Plastic Engineering Co.)
to obtain a molded product in the form of a box having a size of 8
mm width.times.10 mm height.times.100 mm length.times.1 mm
thickness under the conditions of a cylinder temperature of (Tm of
the liquid crystalline polymer+10)(.degree.C.) and a mold
temperature of 90.degree. C. The box type molded product thus
obtained has the four partition walls having a thickness of 0.8 mm
placed with the equal distance, which was injection molded at the
two gates. When the molded product was ejected, the ejection force
(i.e., mold releasing force) was determined, whereby the mold
releasibility was evaluated.
FIG. 2 shows the perspective vies of the above box type molded
product, wherein the molded product (or article) 3 was injection
molded from the gate position 2 provided at the two positions. The
size of the box type molded article is 8 mm width
(W.sub.2).times.10 mm height (t.sub.2).times.100 mm length
(L.sub.2).
When the above-mentioned ejection force (i.e., mold releasing
force) is smaller, the mold releasability is excellent.
Furthermore, the presence or absence of the deformation by the
ejection pin when released from the mold was visually observed by
the shape of the partition portion of the molded product. This is
the measure for the dimension stability. The results are shown in
Table 1.
TABLE 1
__________________________________________________________________________
Performance of box Liquid type molded product crystalline Retention
Mold Change in polymer Olefinic polymer rate of weld releasing
shape of Amount Amount strength force partition Kind (wt. part)
Kind Mw (wt. part) (%) (kg) portion
__________________________________________________________________________
Example 1 A 100 PE 4.0 .times. 10.sup.5 0.3 22 35 None 2 B 100 PE
4.0 .times. 10.sup.5 0.3 22 35 " 3 C 100 PE 4.0 .times. 10.sup.5
0.3 16 40 " 4 D 100 PE 4.0 .times. 10.sup.5 0.3 15 42 " Comparative
Ex. 1 A 100 -- -- -- 23 92 Yes 2 B 100 -- -- -- 23 92 " 3 C 100 --
-- -- 18 95 " 4 D 100 -- -- -- 16 95 " 5 D 100 PE -- 2.04 13 30 "
__________________________________________________________________________
Box type molded product: 8 mm width .times. 10 mm height .times.
100 mm length .times. 1 mm thickness with 0.8 mm thick partition
Olefinic polymer: PE = polyethylene
Examples 5-17 and Comparative Examples 6-12
The liquid crystalline polymers obtained in Reference Examples 1-4
were dry blended with olefinic polymers and the other additives
listed in Table 2 in amounts shown in Table 2. Thereafter, the
blend was melt kneaded to obtain the pellets, using a twin-screw
extruder having a diameter of 30 mm in which the cylinder
temperature were set to the melting point of each polymer. The
resultant pellets were then fed into the Sumitomo Nestal Promat
40/25 Injection Molding Machine (Sumitomo Heavy Machine Industry
K.K.) and injection molded into weld molded products (X) having a
weld at substantially the center portion thereof and non-weld
molded products (Y) having no weld having a size of 6 mm
W.times.127 mm L.times.1 mm T under the conditions of a cylinder
temperature of Tm+10.degree. C. and a mold temperature of
90.degree. C.
The molded products were adjusted at a temperature of
23.degree..+-.2.degree. C. and a relative humidity of 50.+-.5% for
15 hours or more and, then, the flexural strengths of the weld
molded product (X) having a weld at substantially the center
portion thereof and a non-weld molded product (Y) having no weld
were determined at a spun distance of 25 mm and a strain rate of 1
mm and the retention rate of the weld strength was obtained by
substituting the values of the flexural strengths to the
above-mentioned equation (1):
Furthermore, the above pellets were fed to Toshiba 1S55EPN
injection molding machine (Toshiba Machine Plastic Engineering Co.,
Ltd.) to obtain a molded product in the form of a box having a size
of 8 mm width.times.10 mm height.times.100 mm length.times.1 mm
thickness, as in Example 1 under the conditions of a cylinder
temperature of (Tm of the liquid crystalline polymer+10)
(.degree.C.) and a mold temperature of 90.degree. C.
As in Example 1, when the molded product was ejected, the ejection
force (i.e., mold releasing force) was determined, whereby the mold
releasability was evaluated and also the presence or absence of the
deformation by the ejection pin when released from the mold was
visually observed. Furthermore, the flexural text was carried out
under the conditions of a spun distance of 50 mm and a strain rate
of 3 mm and the strength generating cracks at the weld was
determined. The results are shown in Table 2.
In Table II, the olefine polymers are shown as follows.
PE=polyethylene
PP=polypropylene
PE/P=ethylene/propylene copolymer (mole ratio 83/17)
PE/B1=ethylene/butene-1 copolymer (mole ratio 90/10)
PE/P/HD=ethylene/propylene/1,4-hexadiene (mole ratio 85/8/7)
TABLE 2
__________________________________________________________________________
Liquid crystalline Performance of box type Liquid composition
molded product crystalline Retention Mold Change in polymer Filler
Olefinic polymer rate of weld releasing shape of Amount Amount
Amount strength force partition Strength of Kind (wt. part) Kind
(wt. part) Kind Mw (wt. part) (%) (kg) wall weld
__________________________________________________________________________
Example 5 A 100 Glass fiber 50 PE 4.0 .times. 10.sup.5 0.45 27 25
None 3.7 6 B 100 " 50 PE 4.0 .times. 10.sup.5 0.45 26 25 " 3.6 7 C
100 " 50 PE 4.0 .times. 10.sup.5 0.45 20 32 " 2.5 8 D 100 " 50 PE
4.0 .times. 10.sup.5 0.45 18 32 " 2.5 9 A 100 " 50 PE 4.0 .times.
10.sup.5 0.05 28 45 " 3.8 10 A 100 " 50 PE 4.0 .times. 10.sup.5
1.50 25 22 " 3.5 11 A 100 " 50 PE 3 .times. 10.sup.4 0.45 26 49 "
3.5 12 A 100 " 50 PP 1.5 .times. 10.sup.5 0.45 26 30 " 3.4 13 A 100
" 50 PE/P 1.0 .times. 10.sup.3 0.45 26 31 " 3.5 14 A 100 " 50 PE/B1
1.1 .times. 10.sup.5 0.45 27 32 " 3.6 15 A 100 " 50 PE/P/HD 8
.times. 10.sup.5 0.45 25 35 " 3.4 16 A 100 Glass fiber 40 PE 4.0
.times. 10.sup.5 0.45 23 26 " 3.1 Mica 40 17 A 100 Glass fiber 40
PE 4.0 .times. 10.sup.5 0.45 23 27 " 2.9 Talc 40 Comparative Ex. 6
B 100 " 50 -- -- -- 29 82 Yes Cracking when released 7 B 100 " 50
-- -- -- 27 82 " Cracking when released 8 C 100 " 50 -- -- -- 21 85
" Cracking when released 9 D 100 " 50 -- -- -- 19 85 " Cracking
when released 10 A 100 " 50 PE 8000 0.45 10 69 " 0.7 11 A 100 " 50
P)E 3000 0.45 10 69 " 0.6 12 A 100 " 50 PE 5000 0.45 9 69 " 0.6
__________________________________________________________________________
Examples 18-23
Sample pellets of compositions were produced in the same manner as
Example 5, except that the organic bromine compounds listed in
Table 4 were blended with liquid crystal polymer from the raw
material feed port in the proportions indicated in Table 4 based
upon 100 parts by weight of the liquid crystalline polymer in
Example 1. These pellets were then fed into the Sumitomo Nestal
Promat 40/25 Injection Molding Machine (Sumitomo Heavy Machine
Industry K.K.) and molded into testpieces measuring 0.5 mm
(thickness).times.12.7 mm.times.127 mm, as well as strip testpieces
measuring 0.8 mm (thickness).times.12.7 mm.times.127 mm under
conditions of a cylinder temperature of (the melting point of the
liquid crystalline polymer+10.degree. C.) and a mold temperature of
90.degree. C. A vertical combustion test was then performed
according to UL94 standards using the testpieces to evaluate flame
retardency. The other evaluation tests were carried out in the same
manner as in Example 5.
TABLE 3
__________________________________________________________________________
Performance of box type molded product Liquid Reten- Change
Strength crystalline Organic bromine tion Mold in polymer Filler
Olefinic polymer compound rate of releas- shape of Flame Amount
Amount Amount Amount weld ing parti- Strength retard- (wt. (wt.
(wt. (wt. strength force tion of ency Kind part) Kind part)
Kind*.sup.1 Mw part) Kind*.sup.2 part) (%) (kg) wall (kg) UL-9
__________________________________________________________________________
Example 18 A 100 Glass 50 PE 4.0 .times. 10.sup.5 0.45 FR-1 6 26 26
None 3.4 V-0 fiber 19 A 100 Glass 50 PE 4.0 .times. 10.sup.5 0.45
FR-2 6 26 26 " 3.4 V-0 fiber 20 A 100 Glass 50 PE 4.0 .times.
10.sup.5 0.45 FR-3 6 25 27 " 3.4 V-0 fiber 21 A 100 Glass 50 PE 4.0
.times. 10.sup.5 0.45 FR-4 6 26 26 " 3.3 V-0 fiber 22 A 100 Glass
50 PE 4.0 .times. 10.sup.5 0.45 FR-5 6 25 29 " 3.3 V-0 fiber 23 A
100 Glass 50 PE 4.0 .times. 10.sup.5 0.45 FR-6 6 25 29 " 3.2 V-0
fiber
__________________________________________________________________________
*.sup.1 PE = polyethylene *.sup.2 see Table 4
TABLE 4 ______________________________________ No. Structure
______________________________________ FR-1 Poly(brominated
styrene) obtained by polymerization of a monomer containing 80% by
weight of dibrominated styrene. 15% by weight of monobrominated
styrene, and 5% by weight of tribrominated styrene (bromine
content: 59%) Weight average molecular weight: 30 .times. 10.sup.4
FR-2 Poly(brominated styrene) obtained by polymerization of
tribrominated styrene monomer (bromine content: 68%) Weight average
molecular weight: 30 .times. 10.sup.4 FR-3 Dibrominated polystyrene
obtained by bromination of polystyrene (bromine content: 60%)
Weight average molecular weight: 26 .times. 10.sup.4 FR-4
Tribrominated polystyrene obtained by bromination of polystyrene
(bromine content: 68%) Weight average molecular weight: 25 .times.
10.sup.4 FR-5 Brominated epoxy polymer FR-6 Brominated
polycarbonate ______________________________________
Examples 24-28
Example 5 was further repeated except that carbon black was
formulated as shown in Table 5 below.
The results are shown in Table 5.
TABLE 5
__________________________________________________________________________
Performance of box type Liquid Retention molded product crystalline
rate of Mold Change in polymer Filler Olefinic polymer Carbon black
weld releasing shape Strength Amount Amount Amount Amount strength
force partition of weld Kind (wt. part) Kind (wt. part) Kind Mw
(wt. part) pH (wt. part) (%) (kg) wall (kg)
__________________________________________________________________________
Example 24 A 100 Glass 50 PE 4.0 .times. 10.sup.5 0.45 7 0.2 26 26
None 3.4 fiber 25 A 100 Glass 50 PE 4.0 .times. 10.sup.5 0.45 7 0.5
26 26 " 3.5 fiber 26 A 100 Glass 50 PE 4.0 .times. 10.sup.5 0.45 7
1.0 25 26 " 3.4 fiber 27 A 100 Glass 50 PE 4.0 .times. 10.sup.5
0.45 7 5.0 26 26 " 3.4 fiber 28 A 100 Glass 50 PE 4.0 .times.
10.sup.5 0.45 5 1.0 25 26 " 3.4 fiber
__________________________________________________________________________
*.sup.1 PE = polyethylene
As shown above, the shaped articles of liquid crystalline polymer
composition according to the present invention are excellent in
thermal resistance, mechanical properties, dimensional stability
and mold releasability and also excellent in the weld strength, and
therefore, are suitable for various applications such as electrical
and electronic equipment, precision machinery related equipment,
office equipment, and automobile and vehicular related
equipment.
* * * * *